Re: libc_r not functional with new malloc

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:I think the new malloc broke libc_r.  Running firefox, I get this:
:
:% firefox3
:Fatal error 'Cannot allocate red zone for initial thread' at line ? in=20
:file /usr/src/lib/libc_r/uthread/uthread_init.c (errno =3D ?)
:zsh: abort      firefox3
:
:cheers
:   simon

    No, this is a bug in libc_r not using the proper MAP_* flags when
    it mmap()'s the thread stack or the thread stack's guard page.  The
    kernel previously did not catch the problem but now it does, and I
    fixed libthread_xu to use the proper MAP_ flags.

    Instead of properly generating ENOMEM or some other related failure
    when the user VM map fills up in older kernels would allow MAP_STACK
    mappings to improperly overlap MAP_STACK mapped areas, creating a
    situation where the mapped stack can dive into the non-MAP_STACK
    mapping without generating a VM fault or a guard fault, resulting in
    massive corruption instead of a clean memory allocation error.

    BTW we don't support libc_r any more.  We haven't for a while.
    It is libthread_xu or nothing.

						-Matt